System of protection of liquid-insulated electric apparatus



1,642,407 p 1927' M. BUCHHOLZ SYSTEM OF PROTECTIQN OF LIQUID INSULATED ELECTRIC APPARATUS Filed April 1925 //1 van for; Max Backho/z Patented Sept. 13, 1927.

- UNITED STATES 1,642,407 PATENT OFFICE.

mx nu'cnnonz, or GASSEL, GERMANY.

sYsrnu or rno'rnc'rrou or LIQUID-INSULATED nnno'rnrc APPARATUS;

Application med'aprn ie, 1525', serial No. 23,681, andin Germany February 17, 1924.

My invention has reference to a method and means for protecting electric apparatus operating in an insulating liquid, such as oil transformers, oil switches, grounding throttling coils, 'resistancesand the like, and it is one of the important objects of my-inven tion-to provide a device of very simple construction and great reliability, and adapted to operate before extensive injuries to the ap- I in paratns to be protected can occur by sparking, overloading'or otherdisturbances.

My invention ,is particularly based on, the

fact that in the c'as'e'of disturbances in the;

operation of the apparatus to beprotected or in the case of sparking or other irregularities of operation, or whenever such irregularities are imminent, as well as in the-case of any ebullition or fermentation processes in the oil, serving as an insulatingliquid, bubbles j or which-will operate an; alarm or annunci-, ator device indicating-.Ithe d1sturbance,or'

- which is adapted to efiect both kinds of operations. The vapors ener'atedor the gases formed by decomposition or from other causes may influence the contacting means in.

difierent ways. a

No matter how the or vapors are caused to act on 'thdprotectiyc means-provided for cutting out the apparatus to be as otected or :torv annunciating defects ari's.

mg in consequence of an unnormal working preferable, if not necessary, to

of same, it is 'de the bub les of gases or vaporsrismg mthe liquid so as to-accflmulate themjnear 1o the contacts or the like to be actuated. j

Such accumulationof the gases or vapors ca'nbe efiected in difierent ways,- b.ut in all cases suitable guidingsur'faces-must be provided. v In the drawingsafiix'ed to thisspecification and forming partithereofa de'viceembodyin this invention is illustrated diagrammatic y by way of example, In the'drawings-e Figs. 1 and 2 show'an oil switch arranged 60 in its casing which is connected with means for cutting out the switch or for a'nnunciating a contact in case that, owing to unnor mal workingconditions, such defect should arise '1 being a vertical longitudinal section and Fig. 2 a cross section of the apparatus.

Referring-now to Figs. 1 and 2, m is the vessel or casing containing a supply of insu-.

lating oil a in which a switch 0 is disposed.

In a central opening in the cover 12 closing the casing m is mounted a tubular extension 9 entirely filled withv oil. A float 1- loosely applied against the cover of tube 9, on descendin in the oil, will meet and bridge the terimn'a s a ofa protective circuit compris- 'ing a switch, fuse, alarm or other annunciat ing device (not shown).

: ,If, owing to anunnormal working of the apparatus, which is accompanied byv the generation of "heat, g'as'esor vapors ofde composition are generated'in the oil, the gas ,or vapor bubbles will rise in the liquid. In

order to compel these bubbles to enter the tubular extension g; and todisplace' some of the oil contained therein, thereby causing the float r to "descend,-"guide plates .2? are arranged in slopingpositionion each 'insu-v lator u,'these plates being ,so arranged with respect to the tubular ezr'tension'gthat the as'bubbles meeting the "P guided towards the lower opening ofthe tube q.

f Afsii nilar arrangementis provided in close proximityto the switch 0." A roof-shaped guiding member '0 is" disposed right above 'mounted on a centrallopening of the member "o'fisdisposed a contact. flap a: connected to tothe arrangement of the guiding member '0 also the gas bubbles generated from the oil adjoining the; side of the switch are compelled to accumulate below the contact flap :12.

Besides the forms of construction herein shown and described, the invention is susceptible of a variety of other modifications and forms of application of the princi le of my invention all of which operate su stantially ina similar manner. The means of connecting the contacting device with the releasing circuit" and the switching means are open to changes and alterations without any material importance for the operation of the apparatus according to my invention which in its broad aspects comprises the operation of safety devices for electric ap aratus or the like, adapted for operation by vapors, fumes, gases or similar emanations liberated the switch 0. In. a. tubular extension w and expelled from the insulating medium,

and means adapted to be operatively influenced by such emanations, and connected to fuses or equivalent safety means, the instrumentalities shown and described in this specification as embodiments of these prin-' ciples being susceptible of 'modifications without deviating from the spirit of my invention as set forth in the claim.

In the claim the term gas is meant to 10 comprise also vapors and fumes.

I cla1m: q Protective svstem for liquid insulated electric apparatus comprising an apparatus to be protected, a container surrounding same,

a supply of insulating liquid in said c0ntainer, a. protective circuit, comprising terminais and a "co11tact above said apparatus and a sloping guiding surface below said contact for guiding gas developed in conse- MAX BUCHHOLZ. 

